Tohoku J. Exp. Med., 2016 October, 240(2)

Beneficial Effects of Human Papillomavirus Vaccine for Prevention of Cervical Abnormalities in Miyagi, Japan

NOBUYOSHI OZAWA,¹ KIYOSHI ITO,² TORU TASE,³ HIROHITO METOKI⁴ and NOBUO YAEGASHI⁵

¹Ozawa Women's General Clinic, Sendai, Miyagi, Japan
²Disaster Obstetrics and Gynecology, International Research Institute of Disaster Science, Tohoku University, Sendai, Miyagi, Japan
³Department of Gynecology, Miyagi Cancer Center, Natori, Miyagi, Japan
⁴Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University Faculty of Medicine, Sendai, Miyagi, Japan
⁵Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan

Prevention of cervical cancer has been unsuccessful in Japan because of low rates of cancer screening and vaccination. The Vaccine Adverse Review Committee of the Japanese Government investigated 2,475 adverse events and reported 617 (6.9/100,000) severe cases and 176 (2.0/100,000) cases with chronic pain. The proactive recommendation for human papillomavirus (HPV) vaccination has been suspended since June 2013. In this study, we examined vaccination rate and incidence of abnormal cervical cytology in women aged 20 to 24 years attending cancer screening in Miyagi. Among the 3,272 women who underwent a health check in the fiscal year 2014 (April 2014-March 2015), 332 (10.2%) received a HPV vaccination. The HPV vaccination rates were 42.3%, 10%, 17.5%, 3.8% and 4.0% in women aged 20, 21, 22, 23 and 24 years, respectively. The rates of atypical squamous cells of undetermined significance (ASC-US) or worse were 2.41% (8/332) in women with HPV vaccination and 5.03% (148/2,940) in those without HPV vaccination, indicating a significant decrease in vaccinated women (p = 0.03). ASC-US cases were referred to HPV DNA tests. In addition, the rates of high grade squamous intraepithelial lesion (HSIL) or worse were 0.30% (1/332) in women with HPV vaccination and 0.82% (24/2,940) in those without HPV vaccination, showing the marginal decrease in women who were vaccinated (p = 0.3). Thus, this study indicates that HPV vaccination is associated with a reduction in the incidence of cervical abnormalities, suggesting a need for scientific discussion of reinstatement of proactive recommendation for HPV vaccine in Japan.

keywords —— ASC-US; cervix; cytology; HPV vaccine; uterine cervical cancer screening

© 2016 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2016, 240, 147-151

Correspondence: Nobuyoshi Ozawa, Ozawa Women's General Clinic, 192 Aramachi, Wakabayashi-ku, Sendai, Miyagi 984-0073, Japan.

e-mail:nobuyosi@mva.biglobe.ne.jp